Playing Half Of One Clip With Half Of Second Clip

Michaelb_uk wrote on 10/11/2007, 6:34 AM
I'm using Vegas Movie Studio Platinum.

Using different tracks, I'm trying to play two video clips simultaneously so that the right half of one clip plays with the left half of the other clip.

I think the only way to do this is to have my main video on the Video track and to place my second clip on the overlay track then pan the overlay so that just the right half of the overlay clip plays and overrides the right half of the clip on the video track.

This works to a point. I can pan the overlay clip to select just the right half but the problem is that the half I selected now moves to the centre so instead of playing to the right of the main video it plays centre. Whatever I try, I cannot keep the right half of the overlay clip to the right.

Can anyone help me with this please? Am I going about this the right way to achieve what I want or is there a different way.

Thanks.

Michael

Comments

dogwalker wrote on 10/11/2007, 7:28 AM
I'm not sure I follow, but I think so. I have to admit, I've mainly used only pan and zoom so far, rather than track motion.

However, I was able to do what I think you're asking.

On my main track, I selected P&Z and moved it such that only the left half is showing. Then on the overlay track I selected P&Z and moved it so that only the right half is showing. Of course, I could have flipped those.

Then I played the video and sure enough I was able to see both tracks playing next to each other.

and to make it cooler, you can use keyframes to bring the overlay in while moving the main video out, and then when done with that section, use keyframes to have the main video slide over to fill the screen while the overlay slides out of the way
Michaelb_uk wrote on 10/11/2007, 9:10 AM
That's excellent. Many thanks dogwalker. I've almost got that as I want it now.

I would love to add those key frames for that effect but I can't find out how. I tried the manual but I still couldn't do it.

Would you explain in easy steps how to use those key frames.

I'm really grateful for your help.

Many thanks.

Michael
dogwalker wrote on 10/11/2007, 12:06 PM
Well, you'll have to play with it, as I haven't done that, and unfortunately, I don't think it's possible to have "global" keyframes which you can set or use from within the pan and zoom tool (I hope I'm wrong, if anyone can tell us how, please do).

But here's what I'd try.

First move your timeline slider to the point where you first add the overlay, so you're at a common point on both videos.

Next, open the Pan&Zoom on your main event. At the bottom you'll see an area called "Position" - this is where you can add keyframes. Add a keyframe at time zero (click on the "+" button). So, at keyframe 0 (the start), your main event fills the whole screen.

Now click somewhere else, say 2 seconds later and add another keyframe, and also move the video such that it now covers only half the screen. What will happen is that when you watch the movie, this video will be full-screen and then slide to the right (or left) over two seconds.

Close that P&Z window and open P&Z for the overlay and do something similar, except at keyframe 0, you'll have the video off-screen just to the left (I'm having it slide right). Then move the slider to the same point as before (2 seconds in this example) and position the event half-way across.

So, basically, when you introduce the overlay, it will slide from off-screen to half-way across, while simultaneously the main video will slide to the right, and you'll have a split screen.

Then, to slide the overlay back off, you'll do the opposite.

I hope that helps. I'll check back later if you need anything else, or I'm sure others here might have even better suggestions than I do.

Good luck!
Michaelb_uk wrote on 10/11/2007, 1:01 PM
Thank you dogwalker.

I've been playing around with it and managed to get it to work. I'm not sure exactly what I did yet but with your suggestions and more playing around I'll get the hang of this very useful effect.

I really appreciate your time and help. Excellent support.

Many thanks.

Michael
abelenky wrote on 10/11/2007, 3:25 PM
I did it a completely different way, outlined here:

I started with a static image (PNG format) that was 1/2 bright green, and 1/2 transparent.

I put that image on top of one video, so that the playback was 1/2 green, and 1/2 video.
Then, I put the second track on, chroma-keyed to the bright green. That resulted in the final product: the screen is 1/2 one track, and 1/2 the other track.

The reason I did all this: I encoded the same clip with two different codecs, then put them side-by-side to compare the codecs, and produced the final video with a very high bit-rate/quality. Seeing two codecs side-by-side in the same video helped me spot a color-shift in one codec, not present in the other. I also could see the difference between "blocky-ness" and "blurry-ness" in the codecs.
Michaelb_uk wrote on 10/12/2007, 1:47 AM
Right .....

Thanks again dogwalker, I did get the effect working .. but .. I must have the right half of one clip with the left of the other. This isn't possible without horizontal flipping on one of the clips. The slide-in-out then works but the problem is that everything is the wrong way around in the flipped clip. I can see this working well in scenes where the effect of flipping wouldn't matter but, unfortunately, in my present case it does matter.

This is a great effect and I'm really glad you showed me this. I've now stored this amongst my productivity tools.

Many thanks.

Michael
Michaelb_uk wrote on 10/12/2007, 2:03 AM
This sounds very promising. If I can get this to work then I can keep my clips exactly as they are and place the mask exactly as needed.

I made up a mask in PNG format in Paint Shop Pro as you suggested, half green and half transparent.

I followed your next step with the mask on top of one video and it played back exactly as you said, half green and half video.

This is as far as I got. I have tried adding a second track chroma-keyed to green but I just cannot get this last stage to work.

When you say you put the mask on top of one video, do you mean literally directly on top of the clip in the same track or do you mean you put the mask on top of the video on the track above?

I have 6 tracks in Studio Platinum: 1. Text 2. Video Overlay 3. Main Video 4. Sountrack 5. Music 6. Sound Effects

I have tried the mask on different combinations of 1. 2. and 3. but still can't get that last stage right.

Could you explain which tracks you would put the two video clips and the mask on.

Many thanks.

Michael
abelenky wrote on 10/13/2007, 10:28 PM
To detail my steps a little more precisely:

1.) On track 2 (Video Overlay), put a half green/half clear still image.
2.) On track 3 (Video), put your video clip.
3.) Render this, very high bit-rate, quality, etc, to get a video that is 1/2 video, and 1/2 green.

4.) In a new project, add the newly rendered clip to track 2 (Video Overlay)
5.) Add an VideoFX of Sony ChromaKey to track 2
6.) Put your other side-by-side clib on Track 3 (video).

Track three should only show through where there is bright green on track 2, due to chroma-key. That should result in side-by-side video.

In my original instructions, I forgot step 3 and 4.... hope this helps.